Allergic bronchopulmonary aspergillosis (ABPA) is a disease resultingfrom hypersensitivity to Aspergillus allergens. ABPA is associated with bronchial asthma or cysticf ibrosis (CF). It can worsen clinical conditions, frequent exacerbations and accelerate the bronchial tree remodelling. The pathogenesis of this disease is not fully understood. The diagnosis of ABPA in clinical setting is difficult. It is very probable that the disease occurs more frequently than it has been described. This should stimulate continue studies on ABPA pathogenesis and lead to improvement of ABPA diagnosis. The correct diagnosis of ABPA may improve the results of treatment and diminish bronchial remodelling in bronchial asthma and cystic fibrosis patients.